Is nailed by Alan Moore in this 1986 interview talking about Watchmen and part of what he was attempting to do with it:
I know it’s only a tiny little comic book that goes over there every month and gets seen by a relatively small number of people, many of whom perhaps agree with us anyway, so it’s difficult to see what it’s doing, but I was consciously trying to do something that would make people feel uneasy. In issue #3 I wanted to communicate that feeling of “When’s it going to happen?” Everyone felt it. You hear a plane going overhead really loudly, and just for a second before you realize it’s a plane you look up. I’m sure that everybody in this room’s done that at least once. It’s something over everybody’s head, but nobody talks about it. At the risk of doing a depressing comic book we thought that it would be nice to try and … yeah, try and scare a little bit so that people would just stop and think about their country and their politics.
That was what growing up in the eighties felt to me, too young to pay much conscious attention to politics, but old enough to pick up on the fear, on the almost certainty that the bombs would drop sooner rather than later conveyed not so much through the news and such as through pop culture where the nuclear holocaust was present one way or another, as well as through the huge demonstrations against cruise missiles, the largest demonstrations ever held in the Netherlands and about as useful in the end as the later demos against the War on Iraq would be. Throughout everything, up to at least 1987 and Gorbachov, that dread was there and seeped into everything.
Watchmen was one of the best attempts in any artform to make this inchoate fear visible and I immediately recognised it when I first read the series back in 1989 or 1990, when we’d just passed out from under it. It’s the inevitability of it, the idea that if certain things happened, some unclear threshold was crossed, quite ordinary men and women would have no choice but to order the end of the world, more in sorrow than anger, believing to the end that “better dead than red” made sense.
Because of our baby boomer dominated media we tend to think as the fifties and early sixties as the time when we were most obsessed by our coming atomic doom, but the reality of it was that throughout that time the US could’ve easily destroyed the USSR without the latter being able to do much about it, while by the early eighties the weaponry had advanced enough, was ubiquitous enough, was complex enough that a nuclear war would no longer just be devastating, but fatal to the human race as a whole, could really end our world and looked increasingly likely to do so by accident or paranoia.